Abstract：
Although Turner syndrome is most often sporadic, multigenerational recurrence has been reported more often in the offspring of women with mosaic or variant forms of Turner syndrome. We present a case in which natural conception in a woman with identified 45,X/46,XX mosaicism resulted in a fetus with a gain of a derivative X chromosome. The unexpected fetal finding prompted further cytogenetic evaluation of the patient and subsequent identification of an additional cell line with the same derivative X chromosome, not observed in the initial study. To our knowledge, this is the first case in which further investigation of an abnormal noninvasive prenatal screen resulted in the identification of both maternal and fetal sex chromosome abnormality. We discuss the discordant finding, similar cases, and potential phenotype with respect to skewed X inactivation. We also highlight the use of multiple testing methodologies to characterize the serendipitous identification of a derivative X chromosome.
摘要：
虽然特纳综合征最常散发,据报道，在患有马赛克或变异型特纳综合征的女性后代中，多代复发更为常见。我们介绍了一个案例，在该案例中，具有45，X/46，XX镶嵌性的女性自然受孕导致胎儿获得衍生X染色体。意外的胎儿发现促使对患者进行进一步的细胞遗传学评估，并随后鉴定出具有相同衍生X染色体的其他细胞系。在最初的研究中没有观察到。据我们所知,这是对异常非侵入性产前筛查的进一步调查导致母体和胎儿性染色体异常的第一例。我们讨论不和谐的发现，类似案例,和关于偏斜X失活的潜在表型。我们还强调了使用多种测试方法来表征衍生X染色体的偶然鉴定。
